This standard specifies a method for the determination of easily released sulfide in water and waste water in mass concentration ranging from 0,04 mg/l to 1,5 mg/l. Reduction of the volume of the water sample applied allows the determination of higher mass concentrations. Soluble sulfides will be completely determined and undissolved sulfides will be either completely or partially determined, depending on their solubility and ageing properties. Examples are sulfides of zinc, iron, manganese. The sulfide portion of polysulfides is incompletely determined by this method. Some sulfides cannot be determined, such as mercury sulfide.